arduous, exhausting, strenuous, torturous, gruelling, tortuous, hectic, excruciating, daunting, toughest, intense, rigorous, brutal, harrowing, stressful, intensive, laborious, lengthy, tedious, challenging, weeklong, agonizing, uphill, unforgiving, hellish, exhilarating, monotonous, thrilling, frenetic, yearlong, painstaking, perilous, treacherous, sisyphean, yomp, herculean, roughest, sweltering, physical exertion, backbreaking, sapping, enervating, eventful, rockiest, interminable, hellacious, epic, relentless, painful, ferocious, bumpy, toilsome, protracted, fierce, unrelenting, wrenching, wearisome, enthralling, difficult, torrid, tricky, fittest, boot camp, tumultuous, frustrating, daylong, vigorous, monthlong, exhaustive, rancorous, carbo loading, scorching, riveting, frantic, invigorating, humbling, acrimonious, attritional, gutsy, humid, exacting, regimented, winded, merciless, fatiguing, hourlong, final, hour, tiresome, leisurely, demoralizing, contentious, miserable, exasperating, tense, hilly, frenzied, humiliating, weary, sweaty, joyless, debilitating, racking, uneventful, wracking, enjoyable, fateful

effortful, hard, heavy, labourious, punishing